To make berry sauce, stir together grape juice concentrate, strawberries, blackberries, and blueberries in a saucepan over medium heat until the berries pop, and the mixture begins to bubble. Turn the heat to medium-low, and simmer until thickened, stirring occasionally, 5 to 10 minutes. Once thick, pour into a serving dish, and allow to cool 15 minutes at room temperature, or refrigerate until cold.

Whisk together eggs, cream, milk, and sugar in a bowl until the sugar has dissolved, then whisk in the rice flour, baking powder, cinnamon, clove, and allspice.

Heat an 8 inch nonstick skillet over medium-low heat. Add 1/2 cup of the egg mixture, and cook until firm, then fold in half and remove to a serving plate. Repeat with remaining custard mixture. Spoon the cooled berry sauce over custards to serve.